Default Stock Missing after upgrade from 2.3.3 to 2.3.6 and enabling MSI

[CSP_Alex]

I recently upgraded from 2.3.3-p1 to 2.3.6 and enabled MSI. I wasn't using MSI before as a stock plugin I use wasn't compatible, it now is and I have upgraded to their latest version.
After enabling all the MSI modules and refreshing cache and reindexing etc I don't have anything listed in the stock configuration page for MSI, not even the default that is meant to be created and not allowed to be deleted. This means that when running my stock import the salable qty is always 0 and the developers for that plugin are saying it's because there is no default stock option.

How do I create the default stock? I do have the inventory_stock_1 view

[CSP_Alex]

I have just done a fresh install of 2.3.6 on my development server and i have the default stock and everything works as it should.

My question is now, how do i fix the database on my live site without having to do a fresh install?

I was going to compare the SQL files from both databases but my live site database is nearly 700MB so i have nothing to open that with (i usually use notepad++), but even if i find something how would i go about fixing it?